If Day kicked off on Feb. 19, 1942 with a mock battle involving more than 3,500 Canadian troops and reservists, making it the largest military mobilization yet seen in the province. Even actual prairie wars, such as the 1885 North-West Rebellion, hadn’t been nearly this elaborate. The ultimate result was that, to average Winnipeggers, If Day would have looked remarkably similar to how European civilians experienced real-life Nazi takeovers: Smoke and sounds of gunfire in the city’s outskirts, the sight of routed forces retreating and, finally, lines of enemy troops marching into the downtown. Parts of the city were even subject to blackouts as a protection against air raids. Meanwhile, local radio stations broadcast updates from the fighting until, just after the 9:30 a.m. surrender, radios began echoing with German orders. In the above photo, Canadian forces are seen in the opening stages of the city’s doomed defence.